T-Stat

[Frank]

Correct me if Im wrong . No matter what temp T-stat you run , once its open , its no longer controlling the temp its just wide open and flowing what it can. If you engine runs hotter than the temp of the T-stat , you have a circulation or cooling issue. Yes / No ? Thanks FjR68

[nhdcoye]

Yes that is my understanding as well of the the bi-metallic thermostate operation. If you have a good temp gauge you can actually watch and see the temp rise to 180 - 200' and see it drop when the thermostate opens . You can the watch it cycle turns few times it warms up all of the coolant to a uniform temp.

[Frank]

Thats exactly what happens. Lately its been going to 210 with a 185 T-stat. I have the biggest electric I can get in front of the new crossflo aluminum radiator and I think Im gonna put the direct drive fan back in . It rarely saw 200 let alone 210. I know the newer ones run at 210 , I just dont like it there. FjR68

[Kurt]

As Dave pointed out when the engine is first started you may see the gauge go up to temp and drop back a bit and them back up. This is due to the radiator initially being full of cold water. The first couple of times the tstat opens cold coolant rushes in and the tsat closed back up. The cycle repeats until the radiator coolant is warmed up.


The tstat operation is not just wide open or closed. It varies the amount it's open based on the engine temperature.
For a normal cooling system the tstat is just partially opened when the engine is up to operating temp.
As the engine works harder generating more heat the tstat open up a bit more to increase the flow rate of the cooled water from the radiator in order to maintain the tstat set temperature of say 180 degrees.
IF the cooling system has a problem, scaled up radiator, bad fan clutch, clogged water jacket, collapsed hose etc the tsat will open all the way up in an attempt to maintain the set temperature..
Due to the restricted cooling flow or poor air flow the engine temp will then begin to rise past normal temp since the cooling system is not transferring heat out of the engine fast enough.

[Posimoto]

It's possible the thermostat isn't opening fully. You can check it with a thermometer, pan of water, and heat.

[Frank]

Thanks guys : The last couple times out wheelin I saw 210 a lot. I have a new radiator, The pump was new last year and the t-stat was new also. System is clean and a 50/50 mix. I had to put the fan in front of the radiator so I shimmed the flanges to clear the grill . Its rated at 2500 cfms. I changed the controller to an adjustable one from preset. Never when street driving will it go over 180/185. With the breeze today 175 most of the time driving. Just seams it should stay there even wheeling . I took the direct drive fan off cause it ate the original copper rad at Rausch and just found another one. I also got a 6 blade huge clutch fan from a V-8. I will have to tuck the rad into the grill more to run that one , but it will move more air, I think. Thanks FjR68